Art of hardening and toughening steel.



with t e molten metal of the castin arrE f STAFCFE-S .l'A MES CHUROHWARD,

rarnnrorr ou.

OF NEW YORK, N. Y.

Specification of Letters Patent.

Patented 0st. 9, 1906.

\ Application filed July 13. 1906. Eleria1ll0.269,523.

To all whom it may concern:

Be it known that l, J AMES Cnunonwaan, a subject of the King of Great Britain, residing in the borough 0 Manhattan, in the city, county, and state of New York, have invented certain new and useful Improvements in the Art ofHardening and Toughening Steel, of which the following is a specification. in carryinr out the invention it will suilice to describe the actual process preferably employed in making a hardened-steel plate, al though the procedure may be sli htly varied, as well as the ingredients employed, when dealing with castings for different purposes. For making such a plate take" the roper quantity of open-hearth steel andme t it in combination with about one per cent. of chromium, about one-half of one per cent. of tungsten, percent. of nickel, and about one per cent. of manganese. When the mixture of metals is melted, it is poured on a bed or in a mold com sed of manganese inthe form of the 'blac xid of manganese. Itis only important that t e manganese shall be on the surface of the b or mold, where it will come in contact cooled to about a cherry red heat, the casting is removed from the mold or bed and subjected to pressure to reduce it to the re uired thickness for the plate, the reduction eing preferably from about ten to four in order to properly consolidate the mass. The plate ma now be trimmed, sized, and bored when an where necessary, after which it is heated and immersed in a liquid bath composed of linseed-oil, creosote, and a small proportion of water and then left in said bath until it cools, when the face or part ofv the metal which was exposed to the manganese bed or mold will be found to be very hard, tough, and resistant.

The hardness of the face of the plate and the depth to which this hardening extends will depend on the length of time the hot metal casting remains in the bath-that is, if the metal be very hot when it is immersed in the bath it'will remain longer in the bath to cool than it would if not so hot when immerseq, and hence it will be the harder, or the m tal may be subjected to a series of reheatin s and immersionsin the bath. The treatment in the bath governs the degree of hardness, the strength, and the general durability of the metal.

these may tungsten may 'clude glycerin.

(wolfram,) about one and onehalf pressed casting in Preferably the metal to be hardened will be mixed with small percentages of the four metals namedchromium, tungsten, nickel, and manganese; but the percentages of be varied, and for some uses the from the present invention. For lmseedoil any other oil or fatty sub- V stance may be employed as an equivalent, or

gl cerin' (glycerol) may be used. The Word atty7substances is intended herein to in For creosote (which is a monohydric phenol) any phenol or suitable phenol derivative may be employed as car- )OliC acid, for example. The Word phenol here used is intended to include any one or all of these substances By the word manganese as herein used 1s meant either the metal manganese or anyof its compounds or mixture which will yield manganese by reduction in scribed.

Having thus described my invention, 1

-claim 1. The herein-described improvement in the art of hardening and toughening metals,

whichconsists in mixing with the metal to be treated certain small percentages of the metals chromlum, nlckel, manganese and tungsten, then melting the metals, then casting the same in contact with a surface containlng manganese, then pressing the hot castlng,

and finally immersing the hot and pressedcasting in a bath composed essentially ofa fatty substance and-phenol and allowing it to remain therein until it cools.

be omitted, without departing the process de 2. The hereil'i-described improvement n the art of hardening and'toughenmg metals, 7

which consists in mixing steel .with smallper:

centages of chromium, nickel, tungsten and manganese, then melting this m1xture of metals, then casting the same in contact with a surface containing man anese, then pressing the casting produced, w rile hot, to the thickness required, and finally immersing the a liquid'bath containing a fatty substance, a phenol, and Water.

In witness whereof I have hereunto signed myname, this 12th day of July, 1905, in the presence of two subscribing Witnesses.

. JAMES CHURCHWARD. Witnesses:

-I-I. G. Hose,

WILLIAM J. FIRTH. 

